A cephalometric evaluation of the Biobloc technique using matched normative data.

PATIENTS AND METHOD: The outcome of Biobloc treatment was evaluated on 35 patients, 13 male, 22 female, with Class II, Division 1 malocclusions. Cephalometric radiographs were taken before and after treatment. A control group was generated from published normative data in such a way that each treated case was matched individually for age, sex and treatment time. The cephalometric change during treatment was compared to the natural growth change in the matched control group using a Mann-Whitney U-test. The treatment effect was calculated by subtracting the natural growth change from the treatment change. This was then compared to twice the method error to see if the treatment change was clinically significant. RESULTS: There was both a statistically and a clinically significant reduction in overjet (p < 0.001), overbite (p < 0.001) and angle ANB (p < 0.001) with an increase in angle SNB (p < 0.001). None of the other cephalometric parameters measured showed a significant change except for upper incisor proclination (p < 0.05) and ArGoMe angle (p < 0.05) but these were not clinically significant.